1. Fields of the Invention
The invention relates to a display device for stereoscopic picture display in which information relating to sub-pictures is applied to the display device for displaying a picture composed of the sub-pictures in accordance with a fixed pattern.
The invention also relates to a pick-up device for picking up pictures for stereoscopic display.
2. Description of the Related Art
The principle of stereoscopic display of, for example television pictures is known per se. The picture is split up into two sub-pictures passed on to the left eye and to the right eye, respectively. The viewer wears glasses each passing or not passing one of the two sub-pictures; this is usually effected at the field frequency of the TV picture, with, for example the picture of the odd field being observed by the left eye and the picture of the even field being observed by the right eye.
A display device of this type is described in DE No. 31,46,578A. The display screen is provided with strip-shaped polarizers whose mutual directions of polarization are perpendicular to each other so that the picture is passed on per field in a mutually different polarized manner. With polarized glasses, the viewer then alternately observes the sub-pictures, which results in a three-dimensional picture.
The above-mentioned Patent Specification also states the possibility of changing the direction of polarization per pixel; this change must then be accompanied by a similar change from one sub-picture to the other at the end of the pick-up unit or transmitter.
A drawback of such a device is, inter alia that the (strip-shaped) polarizers are secured to the glass of the display tube in such a way that they correspond to the even and odd lines of the television picture. The position of these lines (or possibly pixels) with respect to the polarizers is, however, not completely fixed but is also determined by the control of the picture height (and picture width); it may change in the course of time due to variation of the deflection and/or the EHT system.
Stereoscopic television picture display can also be realized by displaying the pictures for the left and the right eye alternately via the interlaced (odd and even) fields, whilst an active light shutter switching synchronously with a picture field is placed in front of each eye. However, in this case face flicker occurs at a frequency which is equal to the picture frequency (half the field frequency), i.e. approximately 25 Hz (PAL, SECAM) or 30 Hz (NTSC). This face flicker is experienced as a very troublesome effect, all the more because it is also visible outside the actual picture.
Other systems use two separate picture-generating devices whose pictures are combined to one picture via mirrors or by means of projection. A drawback of these systems is the use of two picture-generating devices and the associated facilities to combine the sub-pictures.
A device of the type described in the opening paragraph is proposed in JP-KoKai No. 58-184929. However, the solution shown in this KoKai requires the use of a picture memory; moreover, the sub-pictures are displayed in an interlaced manner so that face flicker also occurs in this case.